<template>
  <div class="todo-footer">
    <label>
      <input type="checkbox" v-model="isAllChecked"/>
    </label>
    <span> 
      <span>已完成{{todoNum}}</span> / 全部{{todoList.length}}
     </span>
    <button class="btn btn-danger" @click="removeAllDone">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "Footer",
  props:["todoList","changAllDone","removeAllDone"],
  computed:{
    todoNum(){
      return this.todoList.reduce((p,c)=>{
        if(c.done){
          p++;
        }
        return p;
      },0)
    },
    isAllChecked:{
      get(){
        return this.todoNum === this.todoList.length && this.todoList.length;
      },
      set(newVal){
        this.changAllDone(newVal);
      }
    }
  }
};
</script>

<style>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>
